Phased Array Antenna System

Abstract

A phased array antenna system is provided that compensates for rotation along a record orbit by multiple element satellites flying in formation. [Solution] A phased array antenna system 2 comprising a plurality of element satellites each having an antenna element, wherein the plurality of element satellites 10 move on an orbit within a virtual reference plane S on which they move on an orbit together with the plurality of element satellites, in a manner that they rotate around a reference point P in the reference plane at the same angular velocity while maintaining their relative positional relationships with each other, and includes n element satellites arranged at approximately equal intervals along a circumferential direction centered on the reference point, and each element satellite of the n element satellites transfers control information for controlling the excitation weight of the antenna element of that element satellite along the circumferential direction centered on the reference point to another element satellite among the n element satellites that is adjacent in the direction opposite to the specified rotation direction, at a period based on time T / n, which is the rotation period T of the plurality of element satellites around the reference point divided by n.

Description

[Technical Field]

[0001] The present disclosure relates to phased array antenna systems. [Background technology]

[0002] It has been proposed to deploy a large number of small satellites in space, move them on circular orbits in a formation flight, and have these small satellites communicate wirelessly with each other, thereby functioning as a wire-free phased array antenna. For example, Patent Document 1 describes that a plurality of small satellites constitute a phased array antenna system, which relays communications between communication devices on the ground. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7416468 Summary of the Invention [Problem to be solved by the invention]

[0004] In one type of formation flight, for example, multiple element satellites move in an orbit around a reference point, rotating while maintaining their relative positions relative to one another along a record-like orbit. In this type of movement, the multiple element satellites move in an orbit around a reference point, and the directivity of the phased array antenna composed of the antenna elements equipped on each satellite can be affected by this rotation. Therefore, controlling the directivity of the phased array antenna, whose position is constantly changing due to the formation flight, is made even more difficult by this rotation.

[0005] One object of the present disclosure is to provide a phased array antenna system capable of compensating for rotation along a record orbit by multiple element satellites flying in formation. [Means for solving the problem]

[0006] The phased array antenna system according to the present disclosure is a phased array antenna system comprising a plurality of element satellites each provided with an antenna element, wherein the plurality of element satellites move on an orbit together with the plurality of element satellites in a manner that they rotate at the same angular velocity around a reference point in the reference plane while maintaining their relative positional relationships with each other within a virtual reference plane, and the plurality of element satellites include n (n is a natural number of 2 or more) element satellites arranged at approximately equal intervals along a circumferential direction centered on the reference point in a concentric region within a predetermined range of distance from the reference point in the reference plane, and each element satellite of the n element satellites transfers control information for controlling the excitation weight of the antenna element of that element satellite along the circumferential direction centered on the reference point to another element satellite among the n element satellites that is adjacent in the direction opposite to the predetermined rotation direction, at a period based on time T / n obtained by dividing the rotation period T of the plurality of element satellites around the reference point by n. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a phased array antenna system capable of compensating for rotation along a record orbit caused by multiple element satellites flying in formation. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a conceptual diagram showing a schematic configuration of a satellite communication system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram for explaining a formation flight by the phased array antenna system 2 according to the present embodiment. [Figure 3] FIG. 2 is a block diagram showing an example of a functional configuration of an element satellite 10 according to the present embodiment. [Figure 4A] 10A and 10B are diagrams for explaining transfer of excitation weight control information according to the present embodiment. [Figure 4B]10A and 10B are diagrams for explaining transfer of excitation weight control information according to the present embodiment. [Figure 4C] 10A and 10B are diagrams for explaining transfer of excitation weight control information according to the present embodiment. [Figure 5] FIG. 2 is another diagram for explaining the first configuration example of the phased array antenna system 2 according to the present embodiment. [Figure 6A] FIG. 2 is a diagram for explaining a second configuration example of the phased array antenna system 2 according to the present embodiment. [Figure 6B] FIG. 2 is a diagram for explaining a second configuration example of the phased array antenna system 2 according to the present embodiment. [Figure 7A] FIG. 10 is a diagram for explaining a third configuration example of the phased array antenna system 2 according to the present embodiment. [Figure 7B] FIG. 10 is a diagram for explaining a third configuration example of the phased array antenna system 2 according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0010] (1) Overview of Satellite Communications System 1 1 is a conceptual diagram for explaining an overview of a satellite communication system 1 according to this embodiment. The satellite communication system 1 includes a phased array antenna system 2, a transmitter 3, and a receiver 4.

[0011] The phased array antenna system 2 includes a plurality of element satellites 10. At least some of the plurality of element satellites 10 included in the phased array antenna system 2 are arranged in an array. The arrangement of the element satellites 10 is not particularly limited, and may be, for example, linear, planar, lattice, concentric, or other arrangements. In the present disclosure, when distinguishing between the individual element satellites 10 or the configurations included in the individual element satellites 10, symbols such as "A" and "B" may be used.

[0012] In this embodiment, ultra-small element satellites are used as the element satellites 10. The element satellite 10 is one example of an element satellite. For example, the size of one element satellite 10 is several centimeters to several tens of centimeters. The total number N of element satellites 10 constituting the phased array antenna system 2 is not particularly limited. The total number N of element satellites 10 may be several hundred, several thousand, or even tens of thousands or more. The distance between adjacent element satellites 10 is, for example, several centimeters to several tens of centimeters. The distance between adjacent element satellites 10 may be about the same as the wavelength or may be shorter than the wavelength (for example, assumed frequency band = 0.8 GHz to 60 GHz). The altitude of each element satellite 10 is, for example, several hundred kilometers to several thousand kilometers.

[0013] The phased array antenna system 2 may receive a transmission signal transmitted from a transmitter 3. The phased array antenna system 2 may also transmit a transmission signal to a receiver 4. The phased array antenna system 2 may relay communication between the transmitter 3 and the receiver 4. That is, the phased array antenna system 2 may generate a transmission signal based on a signal generated by receiving the transmission signal from the transmitter 3, and transmit the generated transmission signal to the receiver 4. The phased array antenna system 2 may include a plurality of phased array antennas that may be configured by a plurality of element satellites 10. Each of these multiple phased array antennas may individually communicate with a ground station (the transmitter 3 and / or the receiver 4).

[0014] The transmitter 3 and the receiver 4 are not particularly limited. For example, the transmitter 3 and the receiver 4 may be mobile stations such as smartphones. In this case, at least some of the element satellites 10 of the phased array antenna system 2 may form a service link with the mobile stations (transmitter 3 and / or receiver 4). Furthermore, for example, the transmitter 3 and the receiver 4 may be base stations. In this case, at least some of the element satellites 10 of the phased array antenna system 2 may form a feeder link or a service link with the base station (transmitter 3 and / or receiver 4). The transmitter 3 and the receiver 4 may be provided together in one device.

[0015] (2) Formation Flight Fig. 2 is a diagram for explaining a formation flight by the phased array antenna system 2 according to this embodiment. Fig. 2 shows the phased array antenna system 2 according to this embodiment moving on an orbit around the Earth. In the illustrated example, for convenience of explanation, only element satellites 10A, 10B, 10C, and 10R are shown out of the multiple element satellites 10 provided in the phased array antenna system 2.

[0016] The plurality of element satellites 10 included in the phased array antenna system 2 are configured to be capable of performing formation flight. That is, the plurality of element satellites 10 included in the phased array antenna system 2 are configured to be capable of moving around the Earth along an orbit specific to each element satellite 10, while maintaining their relative positional relationships with one another. Fig. 2 shows, as an example, orbits OA, OB, OC, and OR around the Earth for element satellites 10A, 10B, 10C, and 10R, respectively.

[0017] During the formation flight described above, the plurality of element satellites 10 provided in the phased array antenna system 2 are configured to be able to move on the orbit in a manner that rotates while maintaining a relative positional relationship with each other on a record orbit centered on a reference point P within a virtual reference plane that moves on the orbit together with the plurality of element satellites 10. In other words, during the formation flight, the plurality of element satellites 10 provided in the phased array antenna system 2 are configured to be able to move on the orbit so as to rotate (spin on their own axes) around the reference point P at the same angular velocity.

[0018] The record disc orbit may be a concentric orbit centered on a reference point P within a virtual reference plane that moves on an orbit together with a plurality of element satellites 10, and may also be referred to as a GCO (General Circular Orbit). In the example of FIG. 2, one record disc orbit 100 is shown as a circular orbit of a predetermined radius centered on the reference point P. In the example of FIG. 2, the position of the element satellite 10R is assumed to coincide with the reference point P. In the example of FIG. 2, the element satellites 10A, 10B, and 10C are configured to be able to move on an orbit in a manner that rotates around the reference point P (element satellite 10R) at the same angular velocity along the record disc orbit 100 while maintaining their relative positional relationships with each other.

[0019] 2, the element satellites 10A, 10B, and 10C all move on an orbit along a single record disc orbit 100 having the same distance (radius) from the reference point P. However, the record disc orbit of any element satellite 10 provided in the phased array antenna system 2 may have any value of distance (radius) from the reference point P as long as it is centered on the reference point P. In other words, each of the multiple element satellites 10 provided in the phased array antenna system 2 may be configured to be able to move on an orbit in a manner of rotating along one of multiple record disc orbits having different distances (radius) from the reference point P. Furthermore, in the phased array antenna system 2 according to this embodiment, as shown in FIG. 2, an element satellite 10 (element satellite 10R) may be arranged at the position of the reference point P, or the element satellite 10 does not necessarily have to be arranged at the position of the reference point P.

[0020] (3) Functional configuration of element satellite 10 3 is a block diagram showing an example of the functional configuration of the element satellite 10 according to this embodiment. The element satellite 10 includes a control device 11, an adjustment mechanism 12, an antenna 13, an antenna 14, and a transmission / reception circuit 15.

[0021] The control device 11 is a device that controls the overall operation of the element satellite 10. The control device 11 includes one or more processors 111 (hereinafter simply referred to as "processors 111") and one or more storage devices 112 (hereinafter simply referred to as "storage devices 112"). The processor 111 includes a CPU (Central Processing Unit) and the like, and performs various types of information processing. The storage device 112 stores various types of information required for processing by the processor 111. The storage device 112 stores a control program. The control program is a computer program executed by the processor 111, and the functions of the control device 11 are realized by cooperation between the processor 111 and the storage device 112. The control program may be recorded on a computer-readable recording medium.

[0022] The adjustment mechanism 12 is a mechanism for adjusting the position and attitude of the element satellites 10 under the control of the control device 11. In the case of ultra-small element satellites 10 that perform formation flight, the adjustment mechanism 12 may include an electromagnet. The electromagnet can adjust the relative positions of nearby element satellites 10 using magnetic force, thereby maintaining a desired array shape. In this case, it is desirable that adjacent element satellites 10 be positioned within a range where the magnetic fields of the electromagnets can influence each other. The magnetic field generated by the electromagnet acts on the adjustment mechanism 12 of the nearest element satellite 10 but has almost no effect on element satellites 10 positioned further away. This makes it possible to adjust the relative positions and attitudes of adjacent element satellites 10. As described above, using an electromagnet for the adjustment mechanism 12 makes it possible to achieve wireless coupling between the element satellites 10 with a simple configuration. This contributes to reducing the size, weight, and cost of the phased array antenna system 2. The adjustment mechanism 12 is not limited to one that uses a driving force from an electromagnet, and may be, for example, a thruster or a propeller.

[0023] The antenna 13 is an example of an antenna element, and receives radio waves (an example of a signal) transmitted from a transmission source (such as the transmitter 3) and outputs the radio waves to the transmission / reception circuit 15. The antenna 13 also outputs radio waves to an external device (such as the receiver 4) based on a signal generated by the transmission / reception circuit 15. As will be described later, the excitation weight of the antenna 13 may be controlled by signal processing in the transmission / reception circuit 15. Here, the excitation weight is a coefficient for adjusting the amplitude and / or phase of the excitation current (voltage) of the antenna element. The antenna 13 may constitute a transmitting and / or receiving phased array antenna together with antennas 13 provided on other element satellites 10. The directivity of the phased array antenna is determined by the excitation weight of the antennas 13 provided on each element satellite 10.

[0024] The antenna 14 is an example of an antenna element and is used to transfer excitation weights between the element satellites 10. For example, the antenna 14 may receive excitation weight control information contained in radio waves transmitted from another element satellite 10 (for example, another adjacent element satellite 10 in the satellite constellation) and supply this to the control device 11. Furthermore, the antenna 14 may transmit the excitation weight control information supplied from the control device 11 as radio waves directed to another element satellite 10 (for example, another adjacent element satellite 10 in the satellite constellation). Note that the antenna 14 may be integrated with the antenna 13 into a single antenna element.

[0025] The transmission / reception circuit 15 performs predetermined signal processing on signals generated by receiving radio waves with antennas (antennas 13 and 14, etc.) equipped on the element satellite 10. Furthermore, the transmission / reception circuit 15 outputs the signals that have undergone predetermined signal processing to the antennas (antennas 13 and 14, etc.) equipped on the element satellite 10, thereby outputting radio waves from the antennas to the outside. The transmission / reception circuit 15 includes a receiving unit 151, a transmitting unit 152, and a signal processing unit 153.

[0026] The receiving unit 151 performs predetermined signal processing on a signal generated by an antenna provided in the element satellite 10 receiving external radio waves, and outputs the signal to the signal processing unit 153. The receiving unit 151 may be configured with, for example, a low-noise amplifier, and may amplify the output signal from the antenna.

[0027] The transmitting unit 152 is configured with a power amplifier and the like, amplifies the signal output from the signal processing unit 153, and outputs it to an antenna provided in the element satellite 10, thereby causing the antenna to output radio waves to the outside.

[0028] The signal processing unit 153 performs predetermined signal processing such as phase shifting, modulation, and demodulation on the signal supplied from the receiving unit 151. Furthermore, the signal processing unit 153 performs predetermined signal processing and outputs the signal to the transmitting unit 152. The signal processing unit 153 may, for example, control the transmitting and receiving circuit 15 so as to compensate for the phase difference of the signals received by the antennas 13 and 14 between the plurality of element satellites 10. The signal processing unit 153 may perform this control so as to compensate not only for the phase difference caused by the difference in the positions of the plurality of element satellites 10 but also for the phase difference caused by the variation of the element satellites 10 as individual elements (including information measured before the launch of the element satellites 10, etc.).

[0029] The signal processing (amplification, phase shift, modulation, demodulation, etc.) performed by the transmission / reception circuit 15 (receiving unit 151, transmitting unit 152, signal processing unit 153, etc.) is controlled, for example, under the control of the control device 11, so that the excitation weight of the antenna 13 becomes a predetermined value. In this case, the control device 11 controls the transmission / reception circuit 15, for example, based on excitation weight control information, so that the excitation weight of the antenna 13 becomes a desired value. The control device 11 may, for example, receive excitation weight control information transferred from another element satellite 10 via the antenna 14 and store the information in one or more storage devices 112. The control device 11 may, for example, transfer the excitation weight control information to another element satellite 10 via the antenna 14. The excitation weight control information may be calculated to compensate for differences in the positions of the element satellites 10 and variations in the individual element satellites 10 (including information measured before the launch of the element satellites 10, etc.). The excitation weight control information may be calculated by the control device 11 or may be acquired from other devices (other element satellites 10, ground devices, etc.). In particular, as will be described later, in the phased array antenna system 2 according to this embodiment, the element satellites 10 constituting a predetermined element satellite group among the plurality of element satellites 10 may transfer excitation weight control information to each other at a predetermined cycle.

[0030] (4) Transfer of excitation weight control information (4-1) Basic operation 4A, 4B, and 4C are diagrams for explaining transfer of excitation weight control information according to this embodiment.

[0031] As described above, the phased array antenna system 2 according to this embodiment includes a plurality of element satellites 10 that move on an orbit in a manner that rotates in a predetermined rotational direction at the same angular velocity on a record orbit centered on a reference point P while maintaining their relative positional relationships with each other. FIG. 4A shows the reference point P and a reference plane S, which is a plane including the record orbit. In the example of FIG. 4A, the rotation direction of the plurality of element satellites 10 is counterclockwise, but it may also be clockwise. Of the plurality of element satellites 10 included in the phased array antenna system 2 according to this embodiment, n element satellites 10 constitute an element satellite group that transfers excitation weight control information to each other. FIG. 4A shows an element satellite group G1 as an example of an element satellite group. The element satellite group G1 includes 12 element satellites 10 (element satellite 10-1a to element satellite 10-1l) as an example of n element satellites 10. The number n of element satellites 10 that constitutes the element satellite group is not limited to 12 and may be any natural number equal to or greater than 2.

[0032] When the phased array antenna system 2 performs formation flight, the n element satellites 10 that make up the element satellite group G1 are arranged in concentric regions within a predetermined distance from a reference point P. An element satellite 10 (reference satellite) may be arranged at the reference point P, or an element satellite 10 may not be arranged at the reference point P. In the example of FIG. 4A , the concentric region is a region between a circle C1 of a first radius centered at the reference point P and a circle C2 of a second radius centered at the reference point P (a region where the distance from the reference point P is equal to or greater than the first radius and equal to or less than the second radius). Note that, when the element satellites 10 are arranged in a concentric region, it is sufficient that at least a portion of the element satellites 10 (for example, the center of gravity of the element satellite 10 or an arbitrary reference point) is included in the region, and it is not necessarily required that the entire element satellites 10 be included in the region without omission.

[0033] The distance from the reference point P to each of the n element satellites 10 constituting the element satellite group G1 may be the same or different, as long as each element satellite 10 is arranged in the concentric area. In other words, the rotation of the n element satellites 10 around the reference point P during the formation flight of the phased array antenna system 2 may be along a record orbit that has the same distance from the reference point P, or may be along each of a plurality of record orbits that have different distances from the reference point P, as long as each element satellite 10 is arranged in the concentric area.

[0034] The n element satellites 10 constituting the element satellite group G1 are arranged in the concentric region at approximately equal intervals along the circumferential direction centered on a reference point P. In the example of FIG. 4A , a separation angle θ, which is the angle between the reference point P and the two element satellites 10, is shown as the interval between two adjacent element satellites 10. The separation angle θ may be an angle based on an angle (360 degrees / n) obtained by dividing the angle of the entire circumference by the number n of element satellites 10 constituting the element satellite group G1. For example, the separation angle θ may be an angle (360 degrees / n) obtained by dividing the angle of the entire circumference by the number n of element satellites 10 included in the element satellite group G1. For example, when n = 12 as shown in FIG. 4A , the separation angle θ may be 30 degrees (360 degrees / 12). Furthermore, for example, the separation angle θ may be an angle obtained by adding a predetermined shift amount to the angle (360 degrees / n) obtained by dividing the angle of the entire circumference by the number n of element satellites 10 included in the element satellite group. The shift amount may be set arbitrarily, for example, based on the number of element satellites 10 provided in the phased array antenna system 2, the number n of element satellites 10 constituting the group of element satellites, the speed of movement on an orbit (formation flight) of the multiple element satellites 10 provided in the phased array antenna system 2, and the angular velocity of the multiple element satellites 10 around the reference point P during the formation flight.

[0035] During formation flight, under the control of the control device 11 included in that element satellite 10, the n element satellites 10 constituting the element satellite group G1 transfer excitation weight control information for controlling the excitation weight of the antenna 13 included in that element satellite 10 to another adjacent element satellite 10 in the direction opposite to the rotation direction around the reference point P (the rotation direction of the multiple element satellites 10 included in the phased array antenna system 2) at a predetermined cycle. Under the control of the control device 11, each element satellite 10 sequentially controls the excitation weight of the antenna 13 included in that element satellite 10 based on the control information received sequentially at the predetermined cycle. That is, each element satellite 10 updates the excitation weight control information for controlling the excitation weight of the antenna 13 included in that element satellite 10 in synchronization with the cycle of transfer of excitation weight control information between element satellites 10. The period for transferring excitation weight control information among the n element satellites 10 constituting the element satellite group G1 may be a period based on time T / n obtained by dividing the rotation period T around the reference point P of the plurality of element satellites 10 provided in the phased array antenna system 2 by n. Specifically, the period may be T / n, or a value obtained by adding a predetermined shift amount thereto. The shift amount may be set arbitrarily, and may be set, for example, based on the number of element satellites 10 provided in the phased array antenna system 2, the number n of element satellites 10 constituting the element satellite group, the speed of movement on an orbit (formation flight) of the plurality of element satellites 10 provided in the phased array antenna system 2, and the angular velocity of the plurality of element satellites 10 around the reference point P during the formation flight.

[0036] Here, a specific example of transfer of excitation weight control information will be described with reference to Figures 4A, 4B, and 4C. For convenience, a dot pattern is attached to the element satellite 10-1a.

[0037] In FIG. 4A, for example, the element satellite 10-1a is disposed at approximately the 1 o'clock direction with respect to the reference point P, and further, the element satellites 10-1b to 10-1l are sequentially disposed clockwise at approximately equal intervals at an angle of approximately 30 degrees. A notation such as "w1a" written inside the block of each element satellite 10 indicates the excitation weight control information that the element satellite 10 uses to control the antenna 13. For example, in FIG. 4A, "w1a" is written inside the block representing the element satellite 10-1a. This indicates that in the illustrated state, the element satellite 10-1a controls the antenna 13 based on the excitation weight control information w1a.

[0038] Fig. 4B shows the arrangement of satellite group G1 at a time when 1 / 12 (T / 12) of the rotation period T has elapsed since the time in Fig. 4A. In Fig. 4B, 1 / 12 (T / 12) of the rotation period T has elapsed since the state shown in Fig. 4A, and therefore each of element satellites 10-1a to 10-1l has rotated counterclockwise by 30 degrees around reference point P. In Fig. 4B, for example, element satellite 10-1a is arranged in the 12 o'clock direction with respect to reference point P.

[0039] When transitioning from the state of FIG. 4A to the state of FIG. 4B, each element satellite 10 transfers excitation weight control information to an adjacent element satellite 10 in the opposite direction to the rotation direction of each element satellite 10 in the reference plane S. For example, when transitioning from FIG. 4A to FIG. 4B, the element satellite 10-1a transfers excitation weight control information "w1a" to the element satellite 10-1b adjacent in the clockwise direction (the opposite direction to the rotation direction (counterclockwise) of the element satellite 10 in the reference plane S). As a result, in the state of FIG. 4B, the element satellite 10-1b arranged at the 1 o'clock direction controls the antenna 13 of the element satellite 10-1b based on the excitation weight control information "w1a" transferred from the element satellite 10-1a. 4B, the element satellite 10-1a receives the excitation weight control information "w1l" from the element satellite 10-1l adjacent in the rotation direction (counterclockwise direction) within the reference plane S of the element satellite 10. As a result, in FIG. 4B, the element satellite 10-1a arranged at the 12 o'clock direction controls the antenna 13 of the element satellite 10-1a based on the excitation weight control information "w1l" transferred from the element satellite 10-1l.

[0040] Fig. 4C shows the arrangement of satellite group G1 at a time when 1 / 12 (T / 12) of the rotation period T has elapsed since the time in Fig. 4B. In Fig. 4C, 1 / 12 (T / 12) of the rotation period T has elapsed since the state shown in Fig. 4B, and each of element satellites 10-1a to 10-1l has rotated counterclockwise by 30 degrees around reference point P. In Fig. 4C, for example, element satellite 10-1a is arranged in the 11 o'clock direction with respect to reference point P.

[0041] When transitioning from the state of FIG. 4B to the state of FIG. 4C, each element satellite 10 transfers excitation weight control information to an adjacent element satellite 10 in the opposite direction to the rotation direction of each element satellite 10 in the reference plane S. For example, when transitioning from FIG. 4B to FIG. 4C, the element satellite 10-1a transfers excitation weight control information "w1l" to the element satellite 10-1b adjacent in the clockwise direction (the opposite direction to the rotation direction (counterclockwise) of the element satellite 10 in the reference plane S). As a result, in the state of FIG. 4C, the element satellite 10-1b arranged at the 12 o'clock direction controls the antenna 13 of the element satellite 10-1b based on the excitation weight control information "w1l" transferred from the element satellite 10-1a. 4C, the element satellite 10-1a receives the excitation weight control information "w1k" from the element satellite 10-1l adjacent in the rotation direction (counterclockwise direction) within the reference plane S of the element satellite 10. As a result, in FIG. 4C, the element satellite 10-1a arranged at the 11 o'clock direction controls the antenna 13 of the element satellite 10-1a based on the excitation weight control information "w1k" transferred from the element satellite 10-1l.

[0042] As described above, each element satellite 10 (element satellite 10-1a to element satellite 10-1l) of the satellite group G1 rotates counterclockwise around the reference point P at a predetermined rotation period T, while transferring excitation weight control information to other element satellites 10 adjacent in the clockwise direction. Then, each element satellite 10 sequentially controls the antenna 13 equipped in that element satellite 10 based on the excitation weight control information acquired through the transfer. Therefore, while the position of each element satellite 10 (element satellite 10-1a to element satellite 10-1l) of the satellite group G1 rotates counterclockwise around the reference point P at a predetermined rotation period T, the distribution of excitation weights of the antennas 13 equipped in each element satellite 10 of the satellite group G1 is approximately fixed with respect to the reference point P.

[0043] As described above, the phased array antenna system 2 according to this embodiment includes a plurality of element satellites 10 that move on an orbit in a manner that rotates at the same angular velocity on a record orbit centered on a reference point P in the reference plane S while maintaining their relative positional relationships with each other. Of the plurality of element satellites 10, n element satellites 10 are arranged at approximately equal intervals along the circumferential direction centered on the reference point P in a concentric region within a predetermined range of distance from the reference point P in the reference plane S. Furthermore, each element satellite 10 of the n element satellites 10 transfers excitation weight control information for controlling the excitation weight of the antenna 13 of that element satellite 10 to another element satellite 10 among the n element satellites 10 that is adjacent to that other element satellite 10 in the circumferential direction centered on the reference point P in the opposite direction to the rotation direction of the plurality of element satellites 10, in a cycle based on time T / n obtained by dividing the rotation period T of the plurality of element satellites 10 around the reference point P by n. This makes it possible for the phased array antenna system 2 according to this embodiment to compensate for at least a part of the influence of the rotation of the plurality of element satellites 10. This makes it easier to control the directivity of the phased array antenna included in the phased array antenna system 2.

[0044] The phased array antenna system 2 according to this embodiment may perform calibration of the transfer of excitation weight control information at any timing (for example, periodically or when a predetermined condition is satisfied). The calibration may be a process based on the positions of the element satellites 10 included in the phased array antenna system 2. For example, as the calibration, the control device 11 may correct the excitation weight control information acquired from another element satellite 10 to a correction value calculated based on the position of the element satellite 10 including the control device 11 or the other element satellites 10. The positions of these element satellites 10 may be measured by each element satellite 10, or may be measured by another external device (such as an element satellite 10, another spacecraft, or a ground device). The calculation of the correction value may be performed by the control device 11 of each element satellite 10, or may be performed by another external device (such as an element satellite 10, another spacecraft, or a ground device).

[0045] (4-2) Configuration example 1 FIG. 5 is another diagram for explaining the first configuration example of the phased array antenna system 2 according to this embodiment.

[0046] As a configuration example 1, the phased array antenna system 2 according to this embodiment may include any number of element satellite groups including a plurality of element satellites that transfer excitation weight control information to each other centered on a first reference point (the center of the record orbit) in the reference plane. The number of element satellites 10 included in each element satellite group may be any number. Figure 5 shows, as examples of the element satellite groups, an element satellite group G2 including eight element satellites 10, an element satellite group G3 including twelve element satellites 10, and an element satellite group G4 including sixteen element satellites 10.

[0047] 5 shows four concentric circles C1, C2, C3, and C4 centered on reference point P. As shown in the figure, the radius values ​​of the circles C1, C2, C3, and C4 increase in this order. When the phased array antenna system 2 performs a formation flight, the eight element satellites 10 included in the element satellite group G2 are arranged in the concentric area between the circles C1 and C2, the twelve element satellites 10 included in the element satellite group G3 are arranged in the concentric area between the circles C2 and C3, and the sixteen element satellites 10 included in the element satellite group G4 are arranged in the concentric area between the circles C3 and C4.

[0048] The plurality of element satellites 10 constituting each element satellite group are arranged in each concentric region at approximately equal intervals along the circumferential direction centered on a reference point P. For example, the separation angle of the element satellite group G2 (the angle between the reference point P and two adjacent element satellites 10 of the element satellite group G2) may be 45 degrees (360 degrees / 8) obtained by dividing the angle of the entire circumference by 8, the number of element satellites 10 constituting the element satellite group G2, or an angle obtained by adding an arbitrary shift amount thereto. For example, the separation angle of the element satellite group G3 (the angle between the reference point P and two adjacent element satellites 10 of the element satellite group G3) may be 30 degrees (360 degrees / 12) obtained by dividing the angle of the entire circumference by 12, the number of element satellites 10 constituting the element satellite group G3, or an angle obtained by adding an arbitrary shift amount thereto. For example, the separation angle of the element satellite group G4 (the angle between the reference point P and two adjacent element satellites 10 in the element satellite group G4) may be 22.5 degrees (360 degrees / 16), obtained by dividing the angle of the entire circumference by 16, the number of element satellites 10 that make up the element satellite group G4, or an angle obtained by adding an arbitrary shift amount to this.

[0049] The element satellites 10 constituting each element satellite group update excitation weight control information for controlling the excitation weights of the antennas 13 equipped in that element satellite 10 in synchronization with the period of control information transfer between the element satellites 10. The period of transfer of excitation weight control information for the element satellite group G2 may be time T / 8 obtained by dividing the rotation period T around the reference point P of the plurality of element satellites 10 equipped in the phased array antenna system 2 by 8, the number of element satellites 10 constituting the element satellite group G2, or a period obtained by adding an arbitrary shift amount thereto. The period of transfer of excitation weight control information for the element satellite group G3 may be time T / 12 obtained by dividing the rotation period T by 12, the number of element satellites 10 constituting the element satellite group G3, or a period obtained by adding an arbitrary shift amount thereto. The period of transfer of excitation weight control information for the element satellite group G4 may be time T / 16 obtained by dividing the rotation period T by 16, the number of element satellites 10 constituting the element satellite group G4, or a period obtained by adding an arbitrary shift amount thereto.

[0050] The plurality of element satellites 10 included in the phased array antenna system 2 according to this embodiment may be arranged in a substantially lattice pattern within the reference plane S. In particular, among the plurality of element satellites 10 included in the phased array antenna system 2, the element satellite 10 included in the element satellite group that transfers excitation weight control information may constitute a part of the plurality of element satellites 10 arranged in a substantially lattice pattern. In the example shown in Fig. 5, the element satellites 10 included in the element satellite groups G2, G3, and G4 are arranged in a substantially lattice pattern as a whole.

[0051] At least some of the element satellites 10 included in the phased array antenna system 2 according to this embodiment may be arranged linearly or in a substantially polygonal shape. In particular, among the element satellites 10 included in the phased array antenna system 2, the element satellites 10 included in the element satellite group that transfers excitation weight control information may be at least partially arranged linearly or in a substantially polygonal shape in a concentric region within a predetermined range of distance from the reference point P in the reference plane S.

[0052] (4-3) Configuration example 2 6A and 6B are diagrams for explaining configuration example 2 of the phased array antenna system 2 according to this embodiment. For convenience, a dot pattern is applied to the element satellite 10-1a of the satellite group G1 and the element satellite 10-5a of the satellite group G5.

[0053] As a second configuration example, the phased array antenna system 2 according to this embodiment may be provided with a first element satellite group including n element satellites centered on a first reference point (the center of the record orbit) in the reference plane, and a second element satellite group including m element satellites 10 centered on a second reference point, which is an arbitrary reference point different from the first reference point in the reference plane, as element satellite groups including a plurality of element satellites 10 that transfer excitation weight control information to each other.

[0054] 6A shows an element satellite group G1 as a first element satellite group and an element satellite group G5 as a second element satellite group as examples of the element satellite groups. The element satellite group G1 as the first element satellite group may be, for example, the element satellite group G1 centered on the reference point P shown in FIG. 4A.

[0055] The m element satellites 10 included in the second element satellite group are arranged at approximately equal intervals along the circumferential direction centered on the second reference point in a concentric region within a predetermined distance from the second reference point. The separation angle of the second element satellite group (the angle formed between the second reference point and two adjacent element satellites 10 in the second element satellite group) may be, for example, an angle (360 degrees / m) obtained by dividing the angle of the entire circumference by the number m of element satellites 10 constituting the second element satellite group, or an angle obtained by adding an arbitrary shift amount thereto. Note that an element satellite 10 (reference satellite) may or may not be arranged at the second reference point.

[0056] 6A, the eight element satellites 10 included in element satellite group G5 as the second element satellite group are arranged in concentric regions within a predetermined distance range from reference point Q as the second reference point, at approximately equal intervals along the circumferential direction centered on reference point Q. The separation angle of element satellite group G5 (the angle formed between reference point Q and two adjacent element satellites 10 of element satellite group G5) may be, for example, 45 degrees (360 degrees / 8) obtained by dividing the angle of the entire circumference by 8, the number of element satellites 10 that make up element satellite group G5, or an angle obtained by adding any shift amount thereto.

[0057] During formation flight, the m element satellites 10 constituting the second element satellite group transfer excitation weight control information for controlling the excitation weight of the antenna 13 equipped on that element satellite 10 to other adjacent element satellites 10 in the opposite direction to the above-mentioned rotation direction around the second reference point (the rotation direction of the multiple element satellites 10 equipped on the phased array antenna system 2) at a predetermined period under the control of the control device 11 equipped on that element satellite 10.

[0058] Each of the m element satellites 10 constituting the second element satellite group sequentially controls the excitation weight of the antenna 13 provided in that element satellite 10 based on the excitation weight control information received sequentially at the predetermined period under the control of the control device 11. That is, each element satellite 10 updates the excitation weight control information for controlling the excitation weight of the antenna 13 provided in that element satellite 10 in synchronization with the period of transfer of control information between the element satellites 10. The period of transfer of excitation weight control information between the m element satellites 10 constituting the second element satellite group may be a period based on time T / m obtained by dividing the rotation period T around the first reference point of the multiple element satellites 10 provided in the phased array antenna system 2 by m. The period may be T / m or a value obtained by adding a predetermined shift amount to T / m. The shift amount may be set arbitrarily, for example, based on the number of element satellites 10 provided in the phased array antenna system 2, the number m of element satellites 10 constituting the second group of element satellites, the speed at which the multiple element satellites 10 provided in the phased array antenna system 2 move on an orbit (formation flight), and the angular velocity of the multiple element satellites 10 around the first reference point during the formation flight.

[0059] 6A, for example, element satellite 10-1a of satellite group G1 is arranged in the direction of approximately 1 o'clock with respect to reference point P, and further, element satellites 10-1b to 10-1l of satellite group G1 are sequentially arranged at approximately equal intervals in a clockwise direction at an angle of approximately 30 degrees. Also, for example, reference point Q, which is the center of satellite group G5, is arranged in the direction of approximately 9 o'clock with respect to reference point P. Furthermore, element satellite 10-5a of satellite group G5 is arranged in the direction approximately midway between 1 o'clock and 2 o'clock with respect to reference point Q, and further, element satellites 10-5b to 10-5h of satellite group G5 are sequentially arranged at approximately equal intervals in a clockwise direction with reference point Q as the center at an angle of approximately 45 degrees.

[0060] FIG. 6B shows the arrangement of the satellites G1 and G5 at a time point when a quarter (T / 4) of the rotation period T has elapsed from the time point in FIG. 6A.

[0061] 6B, a quarter (T / 4) of the rotation period T has passed since the state shown in FIG. 6A, and each of element satellites 10-1a to 10-1l of satellite group G1 has rotated counterclockwise by 90 degrees around reference point P, as indicated by arrow M1. In FIG. 6B, for example, element satellite 10-1a of satellite group G1 is positioned in the 10 o'clock direction with respect to reference point P.

[0062] 6B, since a quarter (T / 4) of the rotation period T has elapsed since the state shown in FIG. 6A, reference point Q, which is the center of satellite group G5, and each of element satellites 10-5a to 10-5h have rotated counterclockwise by 90 degrees around reference point P, as indicated by arrow M5. In FIG. 6B, for example, reference point Q, which is the center of satellite group G5, is disposed in the 6 o'clock direction with respect to reference point P. Furthermore, each of element satellites 10-5a to 10-5h of satellite group G5 has rotated counterclockwise by 90 degrees around reference point Q, as indicated by arrow m5. In FIG. 6B, for example, element satellite 10-5a of satellite group G5 is disposed in the direction approximately midway between 11 o'clock and 10 o'clock with respect to reference point Q.

[0063] When transitioning from the state of Figure 6A to the state of Figure 6B, each element satellite 10, within each satellite group G, sequentially transfers excitation weight control information from an element satellite 10 adjacent in the rotation direction within the reference plane S of each element satellite 10 to an element satellite 10 adjacent in the opposite direction to the rotation direction, and controls the antenna 13 based on the excitation weight control information.

[0064] For example, element satellite 10-1a of satellite group G1 controls antenna 13 based on the excitation weight control information while sequentially transferring excitation weight control information from element satellite 10-1l adjacent in the counterclockwise direction to element satellite 10-1b adjacent in the clockwise direction. Therefore, although the position of each element satellite 10 of satellite group G1 rotates counterclockwise around reference point P at a predetermined rotation period T, the distribution of excitation weights of antennas 13 provided on each element satellite 10 of satellite group G1 is generally fixed.

[0065] Furthermore, for example, the satellite group G5 rotates counterclockwise around the reference point P. Furthermore, at this time, the element satellite 10-5a of the satellite group G5 controls the antenna 13 based on the excitation weight control information while sequentially transferring excitation weight control information from the element satellite 10-5h adjacent in the counterclockwise direction to the element satellite 10-5b adjacent in the clockwise direction. Therefore, although the relative position of each element satellite 10 of the satellite group G5 within the satellite group G5 rotates counterclockwise around the reference point Q at a predetermined rotation period T, the distribution of the excitation weights of the antennas 13 provided on each element satellite 10 of the satellite group G5 within the satellite group G5 is approximately fixed with respect to the reference point Q. It can be said that the amount of movement of the satellite group G5 around the reference point P is relatively small compared to the distance between the phased array antenna system 2 and the ground station. Therefore, by compensating for the rotation of each element satellite 10 within the satellite group G5 around the reference point Q, it is possible to obtain a sufficient effect of facilitating control of the directivity of the phased array antenna.

[0066] As described above, the phased array antenna system 2 according to this embodiment includes a plurality of element satellites 10 that move on an orbit in a manner that rotates at the same angular velocity on a record orbit centered on a first reference point in a reference plane while maintaining their relative positional relationships with each other. Then, m element satellites 10 out of the plurality of element satellites 10 are arranged at approximately equal intervals along the circumferential direction centered on the second reference point in a concentric region within a predetermined distance from a second reference point, which is an arbitrary reference point different from the first reference point in the reference plane. Furthermore, each element satellite 10 of the m element satellites 10 transfers excitation weight control information for controlling the excitation weight of the antenna of that element satellite 10 to another element satellite 10 among the m element satellites 10 that is adjacent to that other element satellite 10 in the direction opposite to the rotation direction of the plurality of element satellites 10 along the circumferential direction centered on the second reference point, at a period based on time T / m obtained by dividing the rotation period T of the plurality of element satellites 10 around the first reference point by m, and sequentially controls the excitation weight of the antenna 13 included in that element satellite 10 based on the transferred excitation weight control information. This makes it possible for the phased array antenna system 2 according to this embodiment to compensate for at least a part of the influence of the rotation of the plurality of element satellites 10. This makes it easy to control the directivity of the phased array antenna included in the phased array antenna system 2.

[0067] The phased array antenna system 2 according to this embodiment may include any number of element satellite groups including a plurality of element satellites that transfer excitation weight control information to each other and are centered on a second reference point different from the first reference point (the center of the record orbit) in the reference plane. The number of element satellites 10 included in each element satellite group may be any number, and the range of distance from the second reference point of each element satellite group may be different for each element satellite group.

[0068] (4-4) Configuration example 3 7A and 7B are diagrams for explaining configuration example 3 of the phased array antenna system 2 according to this embodiment. For convenience, a dot pattern is applied to the element satellite 10-6a of the satellite group G6 and the element satellite 10-7a of the satellite group G7.

[0069] As a configuration example 3, the phased array antenna system 2 according to this embodiment does not have to include an element satellite group including a plurality of element satellites 10 centered on a first reference point (the center of the record orbit) in the reference plane as an element satellite group including a plurality of element satellites 10 that transfer excitation weight control information to each other. Furthermore, the phased array antenna system 2 according to this embodiment may include, as an element satellite group including a plurality of element satellites 10 that transfer excitation weight control information to each other, a first element satellite group including n element satellites centered on a second reference point that is an arbitrary reference point different from the first reference point (the center of the record orbit) in the reference plane, and a second element satellite group including m element satellites 10 centered on a third reference point that is an arbitrary reference point different from the first reference point (the center of the record orbit) and the second reference point in the reference plane.

[0070] 7A shows an element satellite group G6 as a first element satellite group and an element satellite group G7 as a second element satellite group as examples of the element satellite groups. The element satellite group G6 as the first element satellite group and the element satellite group G7 as the second element satellite group may each have a configuration similar to the element satellite group G5 centered on reference point Q as the second reference point shown in FIG. 6A. For example, the element satellite group G6 as the first element satellite group may include n element satellites 10 (12 in the illustrated example) arranged at approximately equal intervals along the circumferential direction around reference point R in a concentric area within a predetermined distance from reference point R as the second reference point. Furthermore, the element satellite group G7 as the second element satellite group may include m element satellites 10 (8 in the illustrated example) arranged at approximately equal intervals along the circumferential direction around reference point U in a concentric area within a predetermined distance from reference point U as the third reference point.

[0071] For example, during formation flight, n (12 in the illustrated example) element satellites 10 constituting the element satellite group G6 as the first element satellite group may, under the control of the control device 11 provided in the element satellite 10, transfer excitation weight control information for controlling the excitation weight of the antenna 13 provided in the element satellite 10 to other adjacent element satellites 10 in the opposite direction to the above-mentioned rotation direction around reference point R as the second reference point (the rotation direction of the multiple element satellites 10 provided in the phased array antenna system 2) at a predetermined period (a period based on time T / n obtained by dividing the rotation period T by n), and sequentially control the excitation weight of the antenna 13 provided in the element satellite 10 based on the transferred excitation weight control information. Similarly, for example, during formation flight, m ​​(eight in the illustrated example) element satellites 10 constituting the element satellite group G7 as the second element satellite group may, under the control of the control device 11 provided in the element satellite 10, transfer excitation weight control information for controlling the excitation weight of the antenna 13 provided in the element satellite 10 to other adjacent element satellites 10 in the opposite direction to the above-mentioned rotation direction around the reference point U as the third reference point (the rotation direction of the multiple element satellites 10 provided in the phased array antenna system 2) at a predetermined period (a period based on the time T / m obtained by dividing the rotation period T by m), and sequentially control the excitation weight of the antenna 13 provided in the element satellite 10 based on the transferred excitation weight control information.

[0072] In FIG. 7A , for example, reference point R, which is the center of satellite group G6, is arranged in the direction of approximately 3 o'clock with respect to reference point P. Furthermore, element satellite 10-6a of satellite group G6 is arranged in the direction of approximately 1 o'clock with respect to reference point R, and further, element satellites 10-1b to 10-1l of satellite group G6 are sequentially arranged at approximately equal intervals in a clockwise direction at an angle of approximately 30 degrees. Also, for example, reference point U, which is the center of satellite group G7, is arranged in the direction of approximately 9 o'clock with respect to reference point P. Furthermore, element satellite 10-7a of satellite group G7 is arranged in the direction of approximately midway between 1 o'clock and 2 o'clock with respect to reference point U, and further, element satellites 10-7b to 10-7h of satellite group G7 are sequentially arranged at approximately equal intervals in a clockwise direction with reference point U as the center at an angle of approximately 45 degrees.

[0073] FIG. 7B shows the arrangement of satellites G6 and G7 at a time when a quarter (T / 4) of the rotation period T has elapsed from the time shown in FIG. 7A.

[0074] In Fig. 7B, a quarter (T / 4) of the rotation period T has elapsed since the state shown in Fig. 7A, and thus reference point R, which is the center of satellite group G6, and each of element satellites 10-6a to 10-6l have rotated counterclockwise by 90 degrees around reference point P, as indicated by arrow M6. In Fig. 7B, for example, reference point R, which is the center of satellite group G6, is disposed at 12 o'clock with respect to reference point P. Furthermore, each of element satellites 10-6a to 10-6l of satellite group G6 has rotated counterclockwise by 90 degrees around reference point R, as indicated by arrow m6. In Fig. 7B, for example, element satellite 10-6a of satellite group G6 is disposed at 10 o'clock with respect to reference point R.

[0075] 7B, since a quarter (T / 4) of the rotation period T has elapsed since the state shown in FIG. 7A, reference point U, which is the center of satellite group G7, and each of element satellites 10-7b to 10-7h have rotated counterclockwise by 90 degrees around reference point P, as indicated by arrow M7. In FIG. 7B, for example, reference point U, which is the center of satellite group G7, is disposed in the 6 o'clock direction with respect to reference point P. Furthermore, each of element satellites 10-7a to 10-7h of satellite group G7 has rotated counterclockwise by 90 degrees around reference point U, as indicated by arrow m7. In FIG. 7B, for example, element satellite 10-7a of satellite group G7 is disposed in the direction approximately midway between 11 o'clock and 10 o'clock with respect to reference point U.

[0076] When transitioning from the state of Figure 7A to the state of Figure 7B, each element satellite 10, within each satellite group G, sequentially transfers excitation weight control information from an element satellite 10 adjacent in the rotation direction within the reference plane S of each element satellite 10 to an element satellite 10 adjacent in the opposite direction to the rotation direction, and controls the antenna 13 based on the excitation weight control information.

[0077] For example, satellite group G6 rotates counterclockwise around reference point P. Furthermore, at this time, element satellite 10-6a of satellite group G6 controls antenna 13 based on the excitation weight control information while sequentially transferring excitation weight control information from element satellite 10-6l adjacent in the counterclockwise direction to element satellite 10-6b adjacent in the clockwise direction. Therefore, although the relative position of each element satellite 10 of satellite group G6 within satellite group G6 rotates counterclockwise around reference point R at a predetermined rotation period T, the distribution of excitation weights of antennas 13 provided on each element satellite 10 of satellite group G6 within satellite group G6 is approximately fixed with respect to reference point R.

[0078] Furthermore, for example, satellite group G7 rotates counterclockwise around reference point P. Furthermore, at this time, element satellite 10-7a of satellite group G7 controls antenna 13 based on the excitation weight control information while sequentially transferring excitation weight control information from element satellite 10-7h adjacent in the counterclockwise direction to element satellite 10-7b adjacent in the clockwise direction. Therefore, although the relative position of each element satellite 10 of satellite group G7 within satellite group G7 rotates counterclockwise around reference point U at a predetermined rotation period T, the distribution of excitation weights of antennas 13 provided on each element satellite 10 of satellite group G7 within satellite group G7 is approximately fixed with respect to reference point U.

[0079] As described above, the phased array antenna system 2 according to this embodiment includes a plurality of element satellites 10 that move on an orbit in a manner that rotates at the same angular velocity on a record orbit centered on a first reference point in the reference plane while maintaining their relative positional relationships with each other. Among the plurality of element satellites 10, n element satellites 10 are arranged at approximately equal intervals along the circumferential direction centered on the second reference point in a concentric region within a predetermined distance from a second reference point, which is an arbitrary reference point different from the first reference point in the reference plane. Furthermore, among the plurality of element satellites 10, m element satellites 10 are arranged at approximately equal intervals along the circumferential direction centered on the third reference point in a concentric region within a predetermined distance from a third reference point, which is an arbitrary reference point different from the first reference point in the reference plane. Furthermore, each element satellite 10 of the n element satellites 10 transfers excitation weight control information for controlling the excitation weight of the antenna 13 equipped on that element satellite 10 to another element satellite 10 among the n element satellites 10 that is adjacent in the direction opposite to the rotation direction of the multiple element satellites 10 along the circumferential direction centered on the second reference point, at a period based on time T / n obtained by dividing the rotation period T of the multiple element satellites 10 around the first reference point by n, and sequentially controls the excitation weight of the antenna 13 equipped on that element satellite 10 based on the transferred excitation weight control information. Furthermore, each element satellite 10 of the m element satellites 10 transfers excitation weight control information for controlling the excitation weight of the antenna 13 included in that element satellite 10 to another element satellite 10 among the m element satellites 10 that is adjacent in the direction opposite to the rotation direction of the multiple element satellites 10 along the circumferential direction centered on the third reference point, at a period based on time T / m obtained by dividing the rotation period T of the multiple element satellites 10 around the first reference point by m, and sequentially controls the excitation weight of the antenna 13 included in that element satellite 10 based on the transferred excitation weight control information. This makes it possible for the phased array antenna system 2 according to this embodiment to compensate for at least a part of the influence of the rotation of the multiple element satellites 10. This makes it easy to control the directivity of the phased array antenna included in the phased array antenna system 2.

[0080] (Appendix 1) 1. A phased array antenna system comprising a plurality of element satellites each provided with an antenna element, the plurality of element satellites move on the orbit in a manner of rotating at the same angular velocity around a reference point in a virtual reference plane that moves on the orbit together with the plurality of element satellites, while maintaining a relative positional relationship with each other; the plurality of element satellites include n (n is a natural number of 2 or more) element satellites that are arranged at approximately equal intervals along a circumferential direction centered on the reference point in a concentric region within a predetermined range of distance from the reference point in the reference plane, Each element satellite of the n element satellites transfers control information for controlling the excitation weight of the antenna element of that element satellite along a circumferential direction centered on the reference point to another element satellite among the n element satellites that is adjacent in a direction opposite to the predetermined rotation direction, at a period based on time T / n obtained by dividing a rotation period T of the plurality of element satellites around the reference point by n. Phased array antenna system. (Appendix 2) 2. The phased array antenna system of claim 1, wherein the n element satellites are arranged along a circumferential direction centered on the reference point and spaced apart by an angle based on an angle obtained by dividing an angle of the entire circumference by n. (Appendix 3) 2. The phased array antenna system according to claim 1, wherein the n element satellites constitute a part of a plurality of element satellites arranged in a lattice pattern among the plurality of element satellites in the region. (Appendix 4) the plurality of element satellites further include m (m is a natural number of 2 or more) element satellites arranged at approximately equal intervals along a circumferential direction centered on a second reference point in a concentric second region, the distance from which is within a second predetermined range from a second reference point different from the reference point in the reference plane, 2. The phased array antenna system according to claim 1, wherein each element satellite of the m element satellites transfers second control information for controlling excitation weights of the antenna elements of that element satellite along a circumferential direction centered on the second reference point to another element satellite among the m element satellites that is adjacent in a direction opposite to the predetermined rotation direction, at a second period based on time T / m obtained by dividing the rotation period T by m. (Appendix 5) 1. A phased array antenna system comprising a plurality of element satellites each provided with an antenna element, the plurality of element satellites move on the orbit in a manner that they rotate at the same angular velocity around a first reference point in a virtual reference plane that moves on the orbit together with the plurality of element satellites, while maintaining a relative positional relationship with each other; The plurality of element satellites include: n element satellites arranged at approximately equal intervals along a circumferential direction centered on a second reference point in a concentric first region, the distance from which is within a first predetermined range from a second reference point different from the first reference point in the reference plane; m element satellites arranged at approximately equal intervals along a circumferential direction centered on the third reference point in a concentric second region in which a distance from the third reference point different from the first reference point and the second reference point in the reference plane is within a second predetermined range, Each element satellite of the n element satellites transfers first control information for controlling the excitation weight of the antenna element of that element satellite along a circumferential direction centered on the second reference point to another element satellite among the n element satellites that is adjacent in a direction opposite to the predetermined rotation direction, in a first period based on time T / n obtained by dividing a rotation period T of the plurality of element satellites around the first reference point by n. Each element satellite of the m element satellites transfers second control information for controlling the excitation weight of the antenna element of that element satellite along a circumferential direction centered on the second reference point to another element satellite among the m element satellites that is adjacent in a direction opposite to the predetermined rotation direction, in a second period based on time T / m obtained by dividing the rotation period T by m. Phased array antenna system.

[0081] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those illustrated and can be modified as appropriate. Furthermore, configurations shown in different embodiments can be partially substituted or combined with each other. [Explanation of symbols]

[0082] 1...satellite communications system, 2...phased array antenna system, 3...transmitter, 4...receiver, 10...element satellite, 10A, 10B, 10C, 10R...element satellite, 11...controller, 12...adjustment mechanism, 13...antenna, 14...antenna, 15...transmitting / receiving circuit, 100...record disc orbit, 111...processor, 112...storage device, 151...receiving unit, 152...transmitting unit, 153...signal processing unit, G1, G2, G3, G4, G5, G6, G7...element satellite group, OA, OB, OC, OR...orbit, P...reference point, Q...reference point, R...reference point, S...reference plane, T...rotation period, θ...separation angle

Claims

1. 1. A phased array antenna system comprising a plurality of element satellites each provided with an antenna element, the plurality of element satellites move on the orbit in a manner that, within a virtual reference plane on which they move on the orbit together with the plurality of element satellites, they rotate in a predetermined rotational direction at the same angular velocity around a reference point within the reference plane while maintaining a relative positional relationship with each other, the plurality of element satellites include n (n is a natural number of 2 or more) element satellites that are arranged at approximately equal intervals along a circumferential direction centered on the reference point in a concentric region within a predetermined range of distance from the reference point in the reference plane, each element satellite of the n element satellites transfers control information for controlling the excitation weight of the antenna element of that element satellite along a circumferential direction centered on the reference point to another element satellite among the n element satellites that is adjacent in a direction opposite to the predetermined rotation direction, at a period based on time T / n obtained by dividing a rotation period T of the plurality of element satellites around the reference point by n; Phased array antenna system.

2. 2. The phased array antenna system according to claim 1, wherein the n element satellites are arranged along a circumferential direction centered on the reference point at angles spaced apart based on an angle obtained by dividing an angle of the entire circumference by n.

3. 2. The phased array antenna system according to claim 1, wherein the n element satellites constitute a part of a plurality of element satellites arranged in a lattice pattern among the plurality of element satellites in the region.

4. the plurality of element satellites further include m (m is a natural number of 2 or more) element satellites arranged at approximately equal intervals along a circumferential direction centered on a second reference point in a concentric second region, the second reference point being different from the reference point in the reference plane, the second region being a second predetermined range of distances from the second reference point, 2. The phased array antenna system according to claim 1, wherein each element satellite of the m element satellites transfers second control information for controlling excitation weights of the antenna elements of that element satellite along a circumferential direction centered on the second reference point to another element satellite among the m element satellites that is adjacent to that element satellite in a direction opposite to the predetermined rotation direction, at a second period based on time T / m obtained by dividing the rotation period T by m.

5. 1. A phased array antenna system comprising a plurality of element satellites each provided with an antenna element, the plurality of element satellites move on the orbit in a manner such that, within a virtual reference plane on which the plurality of element satellites move on the orbit together with the plurality of element satellites, they rotate in a predetermined rotational direction at the same angular velocity around a first reference point within the reference plane while maintaining a relative positional relationship with each other, The plurality of element satellites include: n (n is a natural number of 2 or more) element satellites arranged at approximately equal intervals along a circumferential direction centered on a second reference point in the reference plane, the second reference point being different from the first reference point, in a concentric first region within a first predetermined range of distance from the second reference point; m (m is a natural number of 2 or more) element satellites arranged at approximately equal intervals along a circumferential direction centered on the third reference point in a concentric second region, the distance from which is within a second predetermined range from the first reference point and a third reference point different from the second reference point in the reference plane, each element satellite of the n element satellites transfers first control information for controlling excitation weights of the antenna elements of that element satellite along a circumferential direction centered on the second reference point to another element satellite among the n element satellites that is adjacent in a direction opposite to the predetermined rotation direction, in a first period based on time T / n obtained by dividing a rotation period T of the plurality of element satellites around the first reference point by n; each element satellite of the m element satellites transfers second control information for controlling the excitation weight of the antenna element of that element satellite along a circumferential direction centered on the second reference point to another element satellite among the m element satellites that is adjacent in a direction opposite to the predetermined rotation direction, in a second period based on time T / m obtained by dividing the rotation period T by m; Phased array antenna system.

Images